A hand-held power tool, such as a chain saw, may use a switch device for actuation of electrical supply in the hand-held power tool. Generally, rocker type switch device are used in the hand-held power tools. However, other types of switch device, such as, but not limited to, toggle switch device, push button switch device, momentary switch device, or the like may also be used in similar operations.
The switch devices used in the hand-held power tool include one or more chambers to accommodate an operational member and a contact member. The hand-held power tool may encounter external particulate materials around/into the switch device while the hand-held power tool is in operation. The external particulate materials may include saw dust, dirt, or the like. These external particulate materials may affect the overall performance of the switch device.
Various measures have been adopted in the art to protect the operational member and the contact member of the switch device. One way is to seal the contact member that may at least partly reduce abrasion between the contact member and a pressing member. In other cases, measures have been taken to enclose the switch device within a protective housing to protect the switch device from the external environment.